These are the Gotoh-style tuners on an Ibanez SR 305 DX, yes?
Can't absolutely say for sure, but it could well be that the securing nuts on the headstock face are too tight.
I had a really cantankerous tuner on my Aria SB-900 a while back - it was a pig to adjust, really stiff - & found that this was the cause.
Here's a photo of the tuner I replaced:
The arrow points to a gouged out portion of the securing thread, the locknut was pinching the threaded barrel against the tuning post which was starting to score. Sooner or later something would have sheared.
Take the strings off & slacken all the nuts off, then wind them up until they're finger tight & then give them a "nip" with a spanner - about a quarter turn should be plenty, just enough for them to hold.
Pete.